1998 Buick Riviera Q&A

1998 Buick Riviera Question: After turning the car off there is a loud hum noise coming from the back left

The loud constant humming noise stops after about 1 minute and will sometimes start up again while just sitting there. Could this be the fuel pump?? It's supercharged and the noise seems to be coming from above the drivers rear tire. Thanks -
Answer 1
poss air shock pump? -